Hello,
On 03/03/2011 08:51 AM, Alexander Nozdrin wrote:
> 3367 Alexander Nozdrin 2011-03-03
> A patch for Bug#11763413 (invalid memory reads when PS selecting
> from information_schema tables).
>
> The problem was in some corner cases TABLE instance might have
> NULL 's' attribute (a pointer to TABLE_SHARE).
Which corner cases?
> === modified file 'mysql-test/t/ps.test'
> --- a/mysql-test/t/ps.test 2010-11-13 15:05:02 +0000
> +++ b/mysql-test/t/ps.test 2011-03-03 07:51:42 +0000
> @@ -3344,7 +3344,19 @@ connection default;
> DROP TABLE t1;
> disconnect con1;
>
> +--echo
> --echo #
> ---echo # End of 6.0 tests.
> +--echo # Bug#56115: invalid memory reads when PS selecting from
> +--echo # information_schema tables
> +--echo # Bug#58701: crash in Field::make_field, cursor-protocol
> +--echo #
> +--echo
> +
> +SELECT *
> +FROM (SELECT 1 UNION SELECT 2) t;
> +
> +
> +--echo #
> +--echo # End of 5.5 tests.
I'm unable to reproduce the original problem with this test case and
your change reverted. Is it OS specific? (I tested with
--cursor-protocol as well).
> === modified file 'sql/field.cc'
> --- a/sql/field.cc 2011-02-08 15:47:33 +0000
> +++ b/sql/field.cc 2011-03-03 07:51:42 +0000
> @@ -1552,7 +1552,8 @@ void Field_num::add_zerofill_and_unsigne
>
> void Field::make_field(Send_field *field)
> {
> - if (orig_table&& orig_table->s->db.str&&
> *orig_table->s->db.str)
> + if (orig_table&& orig_table->s&&
> + orig_table->s->db.str&& *orig_table->s->db.str)
> {
> field->db_name= orig_table->s->db.str;
> if (orig_table->pos_in_table_list&&
Even with this change, I'm able to reproduce the problem from Bug#56115
using the bug56115.c test case Shane posted.
--- Jon Olav
